Introduction: Strategies used to induce deep hypothermia during complex neonatal cardiac surgery may influence perioperative and neurological outcomes. Objective: To evaluate the neurological outcomes of rapid cooling in patients undergoing Stage I Norwood palliation for hypoplastic left heart syndrome. Methods: We conducted a retrospective analysis of 49 consecutive neonates with HLHS who underwent the Norwood procedure at the Children’s University Hospital in Cracow between 2019 and 2024. Patients were cooled to deep hypothermia using either a rapid cooling protocol (RC, n=21) or a conventional non-rapid cooling approach (non-RC, n=28). Results: Most patients were male (n=41, 83.7%). Median age at surgery was 9 days [Q1; Q3] [7; 12], and median weight was 3,592 g [3,300; 3,815]. Target temperatures were significantly lower in the RC group (12.9°C vs. 15.5°C, p